Machine for forming hollow articles from pulp



(No Model.)

W. W. MGBWAN. MAGHI-NB FOR FORMING HULLOW. ARTICLES PROM PULP.

N0.4Qo,o3'7j Patented Jan. 17, 189s.

UNrTnn STATES WILLIAM XV. MCEWAN, OF BELVIDERE, NEW JERSEY.

PATENT rms,

MACHINE FOR FORNHNG HOLLOW ARTICLES FROM PULP.

\ SPECIFICATION forming part of Letters Patent No. 490,037, datedJanuary 1'7, 1893.

Application filed December 19, 1891. Serial No. 415,604. (No model.)

.To all whom it may concern:

Be it known that I, WILLIAM W. MCEWAN, of Belvidere, in the county ofWarren and State of New Jersey, have invented certain new and usefulImprovements in Machines for Forming I-Iollow Articles from Pulp; and Ido hereby declare that the following is a full and exact descriptionthereof, reference being had to the accompanying drawings, and to l ageand pressure without drying, and producing an article that shall bestrong, cohesive and substantially homogeneous in structure, completelyshaped and ready without further manipulation for the subsequentprocesses 0f drying and induration.

The use, in a machine for forming such pulp articles, of a female moldconstructed wholly or partially of rubber, is frequently practiced forthe purpose of securing a gradual and even drainage of wat-er from thefibers of the pulp. This results in an unequal expansion of the elasticenvelope or female mold in response to unequal pressure of the pulpagainst it, and in a product of unequal thickness in its variousportions. A pail or basin formed in such a manner must be turned orsawed to an even thickness after drying, breaking up the surfacelamina-tions of its fibrous structure, which are most nearly completeand contribute greatly to the strength of the article, and leaving arough outer surface which requires iinishing, thereby increasing boththe cost and the structural weakness of the product. On the other hand,if in such a machine the male and female molds are rigid and unyielding,and even if both or either of said molds are perforated for the escapeof water from the pulp, the distribution and consequent density of thepulp are unequal, the drainage of water from different portions thereofcannot be regulated, and the resulting product is uneven in texture andlacking in strength.

My invention is intended to provide animproved machine whereby a gradualand even drainage from the body of the pulp article is produced, andwhereby such drainage may be regulated both manually and automatically,without the disadvantages resulting from the use of an elastic femalemold.

In the drawings, Figure l represents partly in elevation andpartlyinsection,a pailforming machine embodying my improvements; Fig. 2,is a vertical section of a portion of the pail form and female mold, andFig. 3 is a horizont-al section of a portion of the pail form.

The pail form, or male mold A, is formed of theA inwardly inclined barsor rods o., a, engaging at their lower ends with a groove b in thecircular large end B, of the form A; and the perforated smaller end C,with the edge of which the upper ends of the bars a, a, engage. The barsa, a, have intervals between them to permit free passage of water, andare recessed as at c, c, on their outer edges to permit the form A to bewound spirallywith the heavy wire d, the entire form Abeing by suchconstruction materially strengthened against pressure from without. Theform A is further covered on its outer surface by several thicknesses ofwire gauze e,f,gof differeut meshes, the tiner outside to give the paila smooth finish and prevent it from sticking on the mold, and thecoarser within to add strength to the gauze envelope and prevent it fromsagging into the intervals between the bars a, d, under mechanical oratmospheric pressure.

The contour of the form A as completed by the wire gauze covering, issubstantiallythat of the inner surface of the pail to be formed. Theform A, rests on the cylindrical block D, shown in the drawings as cutaway in its inner portion to decrease its weight, and having a diametersomewhat greater than that of the base of the form A, the difference indiameter being equal to the thickness of the edge of the pail to beformed. A removable ring E, adapted to fit closely around the base ofthe form A, and having an outer circumference equal to that of the upperface of the block D, may be placed thereon to facilitate the removal ofthe pail when formed, without exposing it to injury by direct handlingwhile IOO still moist. The cylindrical block D, rests on the base plateF, which slides on guide rails h, h, on the vertically movable platen G.The platen G, moves on guides H, H, to which the female mold isimmovably secured as at z', t', and is supported and moved by the pistonrod I, of the piston J, of a hydraulic press, or by other equivalentmechanism. On lowering the platen G the base plate, block and form,withthe completed pail thereon, are run out on the guide rails h, h, to theposition indicated by dotted lines in Fig. l, and the completed pail isremoved from the form. The block D lits closely within the hollowcylinder K, forming the lower portion of the female mold, and has freeVertical movement therein. The feed pipe L, furnished with a valve j,through which the pulp is introduced, is inserted in the side of thehollowT cylinder K, near its upper end. Packing may be inserted in theblock D, as at 7c, k, to insure a perfectly tight joint and prevent theescape of pulp or water from above. The coneshaped upper portion M, ofthe female mold, including the adjustable perforated end plate N, alsocovered on its lower surface with wire gauze, is madeto conform to theouter surface of the form A, in such a manner as to leave a space P,which, when the platen G carrying the structure of the male mold, isforced upward until the upper surface of the base plate F, is in contactwith the lower edge of the hollow cylinder K, will have substantiallythe shape and dimensions of the pail to be formed, the upper portionthereof, designed to form the bottom of the pail, being, as hereinaftershown, of variable thickness. The pipe O, leads vertically downward fromthe perforated end-plate C, of the form A, through the center of thelarger end B, the block D, and outward through the block D, and thelower edge of the hollow cylinder K, which is recessed to permit itspassage. It is furnished with apertures Z, Z, at the inner surface ofthe larger end B, of the form A,and by use of the valve fv, the vent V,and the valve w, and flexible connection WV, with air pumping apparatus,may be made at will a suction or discharge pipe, exhausting the air inthe interior of the form A or simply draining off water therefrom. Theportion of the pipe O above the perforations Z, Z, serves simply as aguide-rod, as hereinafter described, and might therefore be a solid rodsecured to the pipe, but for convenience I prefer to make it anextension of said pipe.

Within the form A, and immediately below the perforated end-plate C,isthe imperforate plate R vertically movable on the guide or upper portionof the pipe O, furnished with packing p on its upper su rface, andsupported by a spring m which is held in tension by a jam nut n,threaded on the pipe O. The end plate N, of the female mold is carriedon the vertical shaft Q, supported in the framework U, and having aswivel joint q, therein, and is made vertically adjustable by means ofthe screw-thread o, and the hand wheel r. Immediately above the endplate N is the imperforate plate S, vertically movable on the shaft Q,having packing son its lower surface, and pressed downward by the springt, which is held in tension by the jam nut a, threaded on the shaft Q.The upper edge of the coneshaped upper portion M of the female mold ispreferably extended above the usual position of the edge of the plate,forming a shoulder or dam Y to prevent overflow, through which leads adischarge pipe y to carry off water forced through the perforated endplate N, and past the packing s.

While the mechanism for applying pressure, shown and described herein,is that of a hydraulic press, other means for producing and applyingpressure may be used. It is like wise obvious that in forming pails ofdifferent shapes, and having sides and bottoms of differentconformations, as Well as in forming basins, tubs and other articles ofhollow ware, the form of the molds may be suitably varied withoutmaterial departure from the spirit of my invention.

In operation the platen G, is lowered until the base of the form A, isbelow the mouth of the feed pipe L, 'the cylindrical block D, beinghowever retained in contact with the inner surface of the hollowcylinder K, and forming a watertight joint therewith. The space P isthereby enlarged sufficiently to receive enough liquid pulp to formafter pressure a pail of the desired thickness and density of fiber. Theextent to which the platen G is lowered, and the consequent enlargementof the space P,will be dependent on the amount of fiber in the pulp. Thepulp is turned on and flows into the space P, completely filling it andcovering the form A. It is then turned off, and pressure is appliedgradually until the lower edge of the hollow cylinder K and the uppersurface of the base plate F, are in contact. If the water, forced out ofthe pulp by this pressure, is allowed to make its way with the samefreedom through the end plate C, of the form A, the end plate N and thesides of the form A,it causes an unequal distribution of fiber and anunequal drainage therefrom, an undue proportion of the fiber beingcarried to the top of the space P by the direction of the pressure andthe double set of water outlets furnished by the end plate C, and theendplate N. At the same time, it is desirable that drainage should takeplace from both surfaces of the pail bottom in order to produce complete and thorough interlocking of fiber in the portion of the pail mostexposed to strain in use. It is not practicable to produce a more evendrainage by making the interstices in the top of the mold smaller thanthose on the side of the form A; by reason of variations in the texture,consistency and liber of the pulp used under different circumstances.

In the machine shown and described herein the plates R and S, arenormally held against ZOO lthe end plate C and the end plate N, by thesprings m and t respectively, and the perforations in said plates CandNare kepttightly closed by the packing p and s.

The springs m and tare adj usted by means of the jam nuts f/t and u atsuch tension that as the male mold gradually rises they will resist thepressure of the water contained in the upper portion of the space P,prevent drainage through the end plate C, and end plate N, keeping thepulpbetween them in a Asemi -liquid condition, until by drainage throughthe sides of the form A, deposit of ber thereon, and the iilling of thesides of the space I), with partially drained pulp, the formation of thesides of the pail is insured. Under continued pressure, drainage throughthe sides of the ferm A, being cheeked as above shown, the waterpressure against the plates R and S increases beyond the resistance ofthe springs m and t, and drainage through the end plate C and the endplate N is set up and continues until the pail is completely formed.rIhe rapidity of the drainage into the interior of the form A, isreadily increased by suction through the pipe O, which can be applied orshut off by the use of the valves 'u and w.

The end plate N, is made vertically movable by means of the screw threado on the swivel jointed shaft Q, for the purpose of pushing downward thecompleted pail and thus breaking any possible adhesions between the pailand the sides of the female mold.

I do not perforate the sides of the coneshaped upper portion of thefemale mold in order to produce a drainage from both the inner and outersurface of the female mold,but Imake the inner surfaces of the femalemold of smooth metal because I find that such single drainage from'thesides of the pail, combined with drainage from both surfaces of thebottom, results in suiiicient density and interlocking of liber toproduce a strong and durable article, and because the completed pail iscaused by such perforation to stick in the mold, and frequently to bedamaged in removal therefrom. After the pail is completely formed,pressure, and suction through the pipe O, are left on untilin thejudgment ci' the operator the pulp in the pail has been consolidated andrelieved of waterto such an extent as to permit handling. The pressureand suction are then released, and the platen G is lowered until thepail clears the lower edge of the cylinder K, when the male mold is runoff in the manner indicated by the dotted lines in Fig. 1, and the pailremoved from the form A by means of the ringE. The best results are notattained by the operation of the machine automatically and withoutregulation.

The main object of my invention is to provide a machine capable ofadjustment and regulation, containing means whereby a skilled Workman,familiar with the properties of the pulp used, and having in mind theeven distribution and interlocking of fiber to be attained, can so varypressure and drainage in the mold or in different portions thereof as toproduce such results uniformly under various conditions.

I claim as my invention:-

I. In a machine for making hollow Ware from pulp, the combination with afemale mold of a hollow male mold to co-operate therewith and having aperforated end plate and an imperforate plate yieldingly supported belowand in contact with said end plate, substantially as shown anddescribed.

2. In a machine for making hollow ware from pulp, the combination with amale mold of a female mold to co-operate therewith and having aperforated end-plate and an imperforate plate yieldingly supported aboveand in contact with said end plate, substantially as shown anddescribed.

3. In a machine for making hollow ware from pulp, the combination withamale mold, of a female mold to co-operate therewith and having a movableend plate, a supporting frame Work, and a shaft supporting saidendplate, said shaft being screw-threaded to engage said traine-work andhaving a swivel joint, substantially as shown and described.

4. In a machine for making hollow ware from pulp, a mold comprising endplates hav-- ing grooves formed in their lateral and proximate surfaces,bars connecting said end plates and interlocking at their ends with saidgrooves, backing or wrapping Wire wound about said mold on the outeredges of said bars and an envelope of wire gauze about said mold,substantially as shown and described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

WILLIAM W. MCEWAN.

Witnesses:

A. N. Jnsnnnn, E. A. GREELEY.

IOO

